The Shattered Mirror is the name used to refer to the sky of Orbis Viridi.
In the cosmology of Orbis Viridi, the sky is considered to be a great faceted mirror in which our world hangs suspended in the middle. Each of the stars is in turn a reflection of our world, in a different manner. It is in this way that the planes formed, for behind each facet is a different world, with different rules and nature.
According to legend, the Precursors thought to travel to these other realms, and built a great machine to take them to the mirror, that they might explore these worlds. But instead of passing through the mirror and into the reflection, they broke the mirror itself, and revealed the chaos behind it.
After a generation of warfare and strife, the Precursors were able to fight back the screaming chaos from behind the mirror, and with the last power of the civilization, erect The Patch. A massive disk, fashioned from the harnessed souls of the empire, placed into the night sky to seal the hole they had made.
Aspects of the Mirror
The Other Planes
The Other Planes refer to the reflections of Orbis Viridi that are seen in the night sky. Each of these is thought to be another Plane. Lancia Rubinius for example, is thought to be the Plane of Fire, while Gladio Fluvius is believed to be the Plane of Water, for their bright coloring and shine in the night sky.
The Chaos Beyond
Supposedly behind the Mirror lies the Screaming Chaos, the place from which all worlds started yet are utterly separate. Beings of the Chaos Beyond are rumored to spread corruption into the world around them.
The Fallen Shards
When the Mirror was broken by the Precursors, fragments of other worlds fell to ours, in the form of broken planes of reflective material. They supposedly varied in size from that of a hand mirror, to a large gateway, and were said to be great fonts of power relating to the worlds they once were part of.